Search form

You are here

» Dark Matter, Dwarf Galaxies, and Massive Failures in the Halo of the Milky Way

Dark Matter, Dwarf Galaxies, and Massive Failures in the Halo of the Milky Way

Event Details

Event Dates:

Monday, November 12, 2012 - 9:00am

Speaker Name(s):

James Bullock

Speaker Affiliation(s):

University of California, Irvine

Seminar Type/Subject

Event Details & Abstract:

The favored dark energy plus cold dark matter (LCDM) model of cosmology predicts that the Milky Way should be surrounded by thousands of dark matter satellite clumps, in great excess of the observed count of Galactic dwarf satellite galaxies. This mismatch is known as the "missing satellite problem". Recent discoveries in theSloan Digital Sky Survey have revealed a new population of ultra-faint dwarf satellites, motivating excitement within the community that some "missing" LCDM satellites are finally being found. Unfortunately for the theory, the situation is not quite so rosy once the dynamical masses of the known satellites are considered. Specifically, the majority of the most massive dark matter satellites predicted to exist are too dense to host any of the bright satellite galaxies of the Milky Way. This poses a serious puzzle theoretically: either galaxy formation becomes effectively stochastic on scales smaller than ~0.1L* or the central densities of dark matter subhalos are significantly lower than predicted in dissipationless simulations. I discuss some possible solutions to this puzzle from the standpoint of baryonic physics and non-standard dark matter physics.

Why Come to JILA?

Contact Us

Mailing Address

JILA
440 UCB
Boulder, CO 80309

Phone/Fax

303-492-7789 (phone)
303-492-5235 (fax)

About JILA

JILA is a joint physics institute of the University of Colorado at Boulder and the National Institute of Standards and Technology. We support an eclectic and innovative research program that fosters creative collaborations among our scientists. Collaborations play a key role in the pioneering research JILA and the JILA Physics Frontier Center are known for around the world. To learn more, visit our About JILA page.